Differential endocannabinoid regulation of extinction in appetitive and aversive Barnes maze tasks.
CB 1 receptor-compromised animals show profound deficits in extinguishing learned behavior from aversive conditioning tasks, but display normal extinction learning in appetitive operant tasks. However, it is difficult to discern whether the differential involvement of the endogenous cannabinoid system on extinction results from the hedonics or the required responses associated with the disparate tasks. Here, we report that the CB 1 receptor antagonist rimonabant disrupts extinction learning in an aversive, but not in an appetitive, Barnes maze conditioning task. Accordingly, these results provide compelling support for the hypothesis that the endogenous cannabinoid system plays a necessary role in the extinction of aversively motivated behaviors but is expendable for appetitively motivated behaviors.
Harloe
John P
JP
Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
Thorpe
Andrew J
AJ
Lichtman
Aron H
AH
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D063388:Endocannabinoids; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors; D000077285:Rimonabant
D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D000077285:Rimonabant